Manual reset for a switch device

ABSTRACT

A condition responsive switching device has a manual reset provision in which a pressure responsive actuator has a pin providing an output force to be applied against a moveable contact blade of a switch. A wedging member is spring biased between the base and the blade so that upon movement of the moveable blade to an open switch position, the wedging member is moved along adjacent to the blade to hold the blade and thus the contact in an open switch position. After the pressure responsive actuator returns to the normal position, a reset operation is accomplished by a pivoting reset driver which is operated upon pushing a reset button to slide the wedging member against its bias spring back to an initial position to allow the moveable blade to move to a closed switch position.

United States Patent [1 1 Kolbow Dec. 25, 1973 MANUAL RESET FOR A SWITCHDEVICE Primary Examiner--Robert K. Schaefer Assistant ExaminerRobert A.Vanderhye [75] Inventor. ilsltzzgld P. Kolbow, Minneapolis, AtmmeyLam0nt B Koontz et al- [73] Assignee: Honeywell lnc., Minneapolis, Minn.ABSTRACT [22] Filed; June 27, 1972 A condition responsive switchingdevice has a manual reset provision in which a pressure responsiveactuator PP 4 266,796 has a pin providing an output force to be appliedagainst a moveable contact blade of a switch. A wedg- 52 U.S. Cl.337/118, 200/83 2; ing member is Spring biased between the base and the51 Int. Cl. lll0llh 37/36, HOlh 71/58 blade 80 that p movement of themoveable blade [58] Field of Search 200/83 2, 153 H; to an Open Switchposition, the wedgihg member is 335/26. 337/56, 91, 118 130, 5 343, 35moved along adjacent to the blade to hold the blade and thus the contactin an open switch position. After [56] References Cited the pressureresponsive actuator returns to the normal UNITED STATES PATENTSposition, a reset operation is accomplished by a pivoting reset driverwhich is operated upon pushing a reset g et 231 button to slide thewe'dging member against its bias 1 2 2 2 '6 X I spring back to aninitial position to allow the moveable blade to move to-a closed switchposition.

6 Claims, 3 Drawing Figures 20 I3 ll 3| 32 1 MANUAL RESET FOR A SWITCHDEVICE BACKGROUND AND SUMMARY OF THE INVENTION In a co-pendingapplication of Elwyn H. Olson Ser. No. 266,797, filed June 27, 1972, forManual Reset For A Switch Device, a control device is disclosed having asnap action condition responsive actuator for moving a switch to an openposition with a means for maintaining the switch in the open positionuntil a manual reset operation takes place. While such control deviceshaving manual reset are broadly old, the Olson device provides for abiasing member against the moveable contact blade so that when the bladeis lifted from a first to a second position to open the switch by theactuator, a removal of the output force provided by the ac tuatorresults in the moveable blade being held in the second position. Themanual reset operation is accomplished by a reset driver for removingthe force supplied by the biasing member to allow the moveable contactblade to return to the first position.

The present invention provides for an improved control device having abiasing member with a resetting operation. A Wedging biasing member ismounted between the base and the moveable contact blade to slide underthe force of a biasing spring along the surface of the blade tocontinuably apply a loading in a direction in line with a main actuatoroutput member. Upon the moveable contact being lifted by the outputmember, the Wedging member slides along the blade to hold the blade inan open switch position even though the output member of the actuatorreturns to a normal position. The resetting operation is accomplished bya reset driver which engages the Wedging member to slide it back to theinitial position to allow the moveable blade to move to a closed switchposition.

FIG. 1 is a partial cross sectional side view of the switch deviceshowing the Wedging member spring biased against a moveable contactblade;

FIG. 2 is a partial cut-away end view of the device of FIG. 1 showingthe reset driver for engaging the wedging member; i i

FIG. 3 is a partial cross sectional view of the device as shown'in FIG.1 with the Wedging member in a position to hold the moveable contactblade in an open switch position.

DESCRIPTION OF THE INVENTION Referring to FIG. 1, the control device hasa base to which is connected an actuator means 11 of a pressureresponsive snap acting type as shown in the M. E. Russell, U.S. Pat.2,840,669 issued June 24, 1958. A pressure through a fluid filled tube12 connected to a remote condition responsive device or bulb 16 providesa pressure to move the output member or pin 13 upwardly upon a conditionor the temperature of the remote bulb exceeding some predeterminedvalue.

Connected to the base is a fixed switch contact 20 electricallyconnected to a terminal 21. A moveable switch contact 22 is connected toa contact support member or resilient blade 24 attached to base 10 andterminal 25. Blade 24 is inclined with respect to a surface 26 of base10. When contact 22 engages contact 20 an electrical circuit iscompleted between terminals 21 and 25.

A contact blade, Wedging member 31 is slidably, moveable between surface26 of the base and resilient inclined blade 24 and is biased in a normalor first position to the left against blade 24 by a spring 32. The forceof spring 32 is sufficient to maintain Wedging member 31 biased againstblade 24 but not sufficient by itself to provide the force or loading tolift the blade from the position, as shown in FIG. I to open the switch.Wedging member 31 moves to a second position, shown in FIG. 3, whenblade 24 is raised by output member 13.

A reset driver member or button 33 is pivoted on base portion or cover10a at 34 and has a pair of extremities and 51 for engaging the outerends 36 and 37 of Wedging member 31 when the reset driver is pushed tothe dotted line position.

As shown in FIG. 2 Wedging member 31 has a pair of connected portions,52 and 53 for engaging the underside of blade 24. Portions 52 and 53 areconnected at 55 to form a U shape so that when the Wedging member movesto the left under blade 24, portions 52 and 53 straddle pin 13 as shownin FIG. 3. Reset driver 33 engages the extremities 52 and 53 of theWedging member at outer ends 37 and 36 which are higher to insure thatextremities 50 and 51 engage the ends to move member 31 to the right asshown in FIG. 1.

OPERATION OF THE INVENTION As shown in FIG. I, the control device is ina switch close position with an electrical circuit existing betweenterminals 21 and 25. Upon an increase in the temperature of bulb 16above a predetermined temperature, actuator 11 causes pin 13 to moveupwardly to lift the moveable blade 24 to a position as shown in FIG. 3to open the electrical circuit. Wedging member 31 is driven by spring 32to the position as shown in FIG. 3 even though the Wedging member isbiased against blade 24. The force on the blade by the wedging member isinsufficient to lift the blade until pin 13 pro vides the additionalupward force.

Upon the return of the temperature to a normal value, pin 13 returns tothe position as shown in FIG. 1; however, Wedging member 31 remains inthe position as shown in FIG. 3 to hold contact 22 in its raisedposition and thus the switch open. Since blade 24 and the base aresubstantially parallel there is little or no force tending to driveWedging member 31 from its holding position. Upon the operation of thereset driver 33 from the position as shown in FIG. 1 to the dashed lineposition, the reset driver moves Wedging member 31 back to the positionas shown in FIG. 1 to allow moveable contact blade 24 to be lowered to aswitch closed position for normal operation.

The Wedging member 31 slides between the base 10 and moveable contactblade 24 to continually engage the blade under the force of spring 32.With such an invention, the change in dimensions due to tolerancebuild-ups during manufacture of such a device is of little consequenceas Wedging member 31 is free to move along the blade until the blade 24is engaged regardless of any variance in the normal position until anadditional force or loading is applied by pin 13 to the blade, the forcedue to Wedging member 31 is insufficient to lift the blade. Such aninvention provides for ease of manufacture as the tolerances of thedimensions of the parts associated with the improved resetting mechanismneed not be maintained within any close degree of accuracy and yet acontrol device is provided with a simple resetting mechanism.

The embodiments of the invention in which an exclusive property or rightis claimed are defined as follows:

1. In a control device, a base,

actuator means attached to said base and adapted to be responsive to achange in value of a condition, switch means on said base having amoveable contact support member for moving a switch contact to open andclose an electrical circuit, said contact support member being inclinedwith respect to an adjacent surface of said base, connection meansoperably connecting said actuator means to said switch means for movingsaid contact support member from a first position to a second positionupon a predetermined change in value of the condition, wedging meanspositioned in a first position between said moveable contact supportmember and said surface of the base, said wedging means tending to biassaid contact support member in a direction from said first to saidsecond position, said bias being insufficient to move said contactsupport member to said second position so that when said contact supportmember moves to said second position in response to said actuator means,said wedging means moves to a second position to hold said moveablecontact support member in said second position, and reset means operablyconnected to said wedging means to slide said wedging means from saidsecond position to said first position to free said moveable contactsupport member from said second position. 2. The invention of claim 1wherein, said moveable contact support member is a resilient bladeattached at one end to said base and having a switch contact at itsopposite end, and

said wedging means comprises a member mounted between said base and saidblade and biased to slide along said blade as said blade moves from saidfirst to said second position.

3. The invention of claim 2, wherein,

said reset means comprises a lever pivotally connected to said base andhaving extremities for engaging said wedging member to slide saidwedging member from said second to said first position so as to not holdsaid blade in said second position.

4. The invention of claim 1, wherein,

said contact support member is a resilient blade supporting a switchcontact of said switch means,

said connection means comprises a pin engaging said blade of said switchmeans to lift the blade to said second position, andsaid wedging meanscomprises a U-shaped member which is biased by a spring to apply a forceto said blade which is insufficient to move said blade to said secondposition, said U-shaped member being arranged to straddle said pin whensaid pin moves to apply a force to the blade which is sufficient to movesaid blade to said second position.

5. The invention of claim 4, wherein,

said U-shaped member has two in line surfaces on opposite sides thereoffor engaging said blade continuously throughout its movement from saidfirst position to said second position.

6. The invention of claim 4 wherein,

said U-shaped member in said first position applies a force to saidblade regardless of any variance in said first position of said blade.

1. In a control device, a base, actuator means attached to said base andadapted to be responsive to a change in value of a condition, switchmeans on said base having a moveable contact support member for moving aswitch contact to open and close an electrical circuit, said contactsupport member being inclined with respect to an adjacent surface ofsaid base, connection means operably connecting said actuator means tosaid switch means for moving said contact support member from a firstposition to a second position upon a predetermined change in value ofthe condition, wedging means positioned in a first position between saidmoveable contact support member and said surface of the base, saidwedging means tending to bias said contact support member in a directionfrom said first to said second position, said bias being insufficient tomove said contact support member to said second position so that whensaid contact support member moves to said second position in response tosaid actuator means, said wedging means moves to a second position tohold said moveable contact support member in said second position, andreset means operably connected to said wedging means to slide saidwedging means from said second position to said first position to freesaid moveable contact support member from said second position.
 2. Theinvention of claim 1 wherein, said moveable contact support member is aresilient blade attached at one end to said base and having a switchcontact at its opposite end, and said wedging means comprises a membermounted between said base and said blade and biased to slide along saidblade as said blade moves from said first to said second position. 3.The invention of claim 2, wherein, said reset means comprises a leverpivotally connected to said base and having extremities for engagingsaid wedging member to slide said wedging member from said second tosaid first position so as to not hold said blade in said secondposition.
 4. The invention of claim 1, wherein, said contact supportmember is a resilient blade supporting a switch contact of said switchmeans, said connection means comprises a pin engaging said blade of saidswitch means to lift the blade to said second position, and said wedgingmeans comprises a U-shaped member which is biased by a spring to apply aforce to said blade which is insufficient to move said blade to saidsecond position, said U-shaped member being arranged to straddle saidpin when said pin moves to apply a force to the blade which issufficient to move said blade to said second position.
 5. The inventionof claim 4, wherein, said U-shaped member has two in line surfaces onopposite sides thereof for engaging said blade continuously throughoutits movement from said first position to said second position.
 6. Theinvention of claim 4 wherein, said U-shaped member in said firstposition applies a force to said blade regardless of any variance insaid first position of said blade.